BULAaah BULAaaah BULAaaah,
Question (1),In supp techniques FCOM 3.04.27 p9, there is a section on overspeed in terms of automatic A/P disengagement and a 1.75G pull-up in ADDITION to pilot input.
Some serial numbers do display a "G LOAD" at the bottom of the SD.
Reversion scenarios in FCOM 1.22.30 p39 and p42with FD's ON when FD's auto disengage without A/P respectively, while p45 has a mode reversion summary. No mention of "G" limits.
In which section did you find these "G" additives?
Question (2), I cannot find any reference in regards to your query of "G" authority/logic and airspeed trend towards VLS. Only that the speed trend arrow usually gives you 10 seconds at the current rate of closure on what speed will be reached which you may know of.
From experience using Expedite mode, a sudden change of wind from head to tail or a rapidly increasing tailwind will feel a more pronounced negative "G" as the speed trend arrow decays to or even below VLS.
I'm sure other posters may have some more info.